diff mbox series

ipv6: ip6_fib: fix possible null-pointer-dereference in ipv6_route_native_seq_show

Message ID 20241101044828.55960-1-03zouyi09.25@gmail.com (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series ipv6: ip6_fib: fix possible null-pointer-dereference in ipv6_route_native_seq_show | expand

Checks

Context Check Description
netdev/series_format warning Single patches do not need cover letters; Target tree name not specified in the subject
netdev/tree_selection success Guessed tree name to be net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 3 this patch: 3
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 1 maintainers not CCed: horms@kernel.org
netdev/build_clang success Errors and warnings before: 3 this patch: 3
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 5 this patch: 5
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 16 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest fail net-next-2024-11-01--06-00 (tests: 780)

Commit Message

Yi Zou Nov. 1, 2024, 4:48 a.m. UTC 
In the ipv6_route_native_seq_show function, the fib6_nh variable
is assigned the value from nexthop_fib6_nh(rt->nh), which could
return NULL. This creates a risk of a null-pointer-dereference
when accessing fib6_nh->fib_nh_gw_family. This can be resolved by
checking if fib6_nh is non-NULL before accessing fib6_nh->fib_nh_gw_family
 and assign dev using dev = fib6_nh ? fib6_nh->fib_nh_dev : NULL;
to prevent null-pointer dereference errors.

Signed-off-by: Yi Zou <03zouyi09.25@gmail.com>
---
 net/ipv6/ip6_fib.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index eb111d20615c..6632ab65d206 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -2555,14 +2555,14 @@  static int ipv6_route_native_seq_show(struct seq_file *seq, void *v)
 #else
 	seq_puts(seq, "00000000000000000000000000000000 00 ");
 #endif
-	if (fib6_nh->fib_nh_gw_family) {
+	if (fib6_nh && fib6_nh->fib_nh_gw_family) {
 		flags |= RTF_GATEWAY;
 		seq_printf(seq, "%pi6", &fib6_nh->fib_nh_gw6);
 	} else {
 		seq_puts(seq, "00000000000000000000000000000000");
 	}
 
-	dev = fib6_nh->fib_nh_dev;
+	dev = fib6_nh ? fib6_nh->fib_nh_dev : NULL;
 	seq_printf(seq, " %08x %08x %08x %08x %8s\n",
 		   rt->fib6_metric, refcount_read(&rt->fib6_ref), 0,
 		   flags, dev ? dev->name : "");